Tumor Vasculature Directed Drug Targeting: Applying New Technologies and Knowledge to the Development of Clinically Relevant Therapies

Recognition of the dependence of solid tumor growth on the formation of new blood vessels has ignited an enormous research effort aimed at the development of new therapeutic strategies for cancer. Besides direct application of drugs inhibiting endothelial cell function during angiogenesis, tumor vasculature directed drug-targeting strategies have been investigated for this purpose. In animal models of disease, proof of principle regarding the potential of selective interference with tumor blood flow as a powerful tumor therapy has been generated to its full extent. The challenge for the coming years will be to develop these strategies into clinically applicable ones. New insights into the molecular mechanisms prevailing in the endothelium during angiogenesis and into the mechanism(s) of action of drugs with anti-angiogenic activities, as well as new techniques to identify useful tumor endothelium specific target epitopes have in recent years been exploited to meet this challenge. This review summarizes vasculature directed therapeutic strategies proven to be successful in pre-clinical models and new (drug targeting) technologies enabling the development of more effective therapeutics for the treatment of cancer.